Summary Aim. The study of group psychotherapy influence on the personality functioning of patients n treatment for neurotic disorders and selected personality disorders (F4-F6 under ICD-10). Methods. The study concerned 82 patients (61 women and 21 men) who underwent intensive short-term group psychotherapy in a day ward. A comprehensive assessment of the patients’personality functioning was carried out at the outset and the end of the psychotherapy utilising the MMPI-2 questionnaire. Results. At the treatment outset the majority of the study patients demonstrated a considerable level of disorders in five MMPI-2 clinical scales (Depression, Hysteria, Psychopathic Deviate, Psychastenia, Schizophrenia) and moderate pathology in Hypochondria. In the Mania scale most patients obtained results comparable to the healthy population when the treatment commenced. Having undergone the psychotherapy treatment, the majority of the examined were observed to demonstrate positive changes in those areas of personality functioning which were classified as severe or moderate pathology. Conclusions. Short-term intensive comprehensive group psychotherapy with elements of individual psychotherapy leads to desirable changes in personality functioning.